Video/audio processing system providing real time program duration alteration

ABSTRACT

The running real time length of combined video and audio signal programs is shortened or lengthened by deleting or repeating individual fields or frames and corresponding amounts of audio segments. The video and audio portions of the programming material are separated and subjected to processing through a pair of program time changing units. The video portion is processed by deleting individual fields or frames on a manual, periodic or automatic basis. Manual deletion is done by an operator observing the program material on a monitor. Periodic deletion is performed automatically after the operator specifies the total amount of time (or number of fields or frames) to be deleted, with every ith frame or field deleted regardless of content. Automatic deletion is done in a fashion similar to periodic deletion, but the fields or frames are examined and are deleted on the basis of the amount of between frame motion. Audio segment deletion is done either manually, periodically or automatically, and the audio segments removed need not match the deleted frame video, but may be taken from different frames, so long as the total time length of the deleted audio segments equals the total time of the deleted video frames, and also provided that the differential delay between the processed video and processed audio does not exceed the lip sync criterion. A pause function disables the deletion or insertion process for program materials which may not be altered in any way.

This is a divisional of application Ser. No. 09/426,844, filed Oct. 26,1999 which is a divisional of application Ser. No. 08/552,357, filedNov. 2, 1995 now U.S. Pat. No. 5,995,153.

BACKGROUND OF THE INVENTION

This invention relates to video signal processing methods and systems.More particularly, this invention relates to methods and systems foraltering the content of video program material to expand or contract thetotal length of an entire program or program segment.

Video signal processing systems and methods are known for editing thecontent of an entire program or program segment in order to expand orcontract the total program run time to match a desired run length ortime segment. Frequently, a program or commercial which is scheduled fora predetermined broadcast time slot has a total running time which doesnot match exactly the time slot. In such cases, it is necessary to editthe program in order to fill the time slot exactly. In known systems,the program material must first be recorded on some suitable recordingmedium, such as magnetic tape, after which portions of the video programare deleted or repeated in order to contract or expand the running timeto match the time slot. Such systems suffer from the disadvantage thatthe program to be edited cannot be simultaneously broadcast, but must betime delayed by the recording process. In addition, this technique isincompatible with live events, such as soccer matches, football gamesand the like, which must be broadcast and viewed substantiallysimultaneously. Efforts to date to provide real time video time editingto contract or expand the program length to match a desired run lengthhave not met with success to date.

SUMMARY OF THE INVENTION

The invention comprises a method and system for providing real timevideo program expansion or contraction which relatively inexpensive toimplement, easy to operate, and effective matching program run time witha predetermined run length. In addition, the invention is effective increating surplus broadcast from any program in order to provideadditional broadcast time for other information, such as commercialspots, public service announcements, and the like.

From a processing standpoint, the invention comprises a method ofadjusting the total time length of a program having a fixed timeduration by deleting or repeating individual frames or fields of videoand audio segments on-the-fly, either on a fixed periodic basis, anautomatic basis or manually using an operator controlled deletion orinsertion circuit. The audio segments may or may not correspond to theframes or fields, but need only match the total time value of thedeleted or repeated video frames or fields.

To contract a given program in the manual mode of operation, theoperator monitors the video program material and deletes one frame orfield at a time. A counter accumulates the time value of the sum ofdeleted frames or fields and displays this total to the operator. Oncethe desired amount of additional broadcast time has been accumulated,the original program material is permitted to be passed throughunmodified. To expand a given program in the manual mode, the operatormonitors the video program material and repeats one frame or field at atime, and the time accumulation counter keeps track of the total amountof time value of the repeated frames or fields and displays thisinformation to the operator. Once the correct amount of time has beenadded to the original program material, the original program material ispermitted to pass through unmodified. During the video deletion orrepetition, corresponding segments of audio are deleted or repeated.

In the periodic mode of operation, the operator enters the total amountof time to be deleted or added to the original program material length,and frames or fields and corresponding audio segments are deleted oradded automatically in a periodic manner, e.g. one frame every fiveframes, one field every five fields, etc. The time counter accumulatesthe running total of deleted or added time, and terminates the deletionor insertion process when the running total equals the preselectedamount.

In the automatic mode of operation, the operator adds the total amountof time to be deleted or added to the original program material length,and frames or fields and audio segments are deleted or addedautomatically, with the choice of particular frames/fields and audiosegments being determined by video motion detectors and audio pitch andlevel detectors, so that optimal deletion or insertion is effected.

In both the periodic and automatic modes of operation, an optional pausefunction protects any specially selected sensitive programming materialfrom being affected by the time change processing. The pause functionitself may be manually controlled by an operator, or automaticallyperformed by detecting special marker information inserted inpredetermined frames/fields, or in reserved portions of same (i.e.during vertical blanking).

The invention enables on-the-fly adjustment of the running time ofprogram material without affecting the actual broadcast of the programmaterial. In addition, for programs of indeterminate length, theinvention enables a fixed amount of time to be added or deleted over apreselected time period. For example, the invention can be used to gaina preselected fixed amount of time—e.g. ten minutes over a one hourbroadcast time period—using either the manual or periodic modes ofoperation. Most importantly, the time deletion or insertion does notvisibly affect the program content as experienced by the viewer, so thatthe program material can be enjoyed to the same extent as the originalprogram material.

For a fuller understanding of the nature and advantages of the inventionreference should be made to the ensuing detailed description of theinvention, taken in conjunction smith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a video and audio processing systemincorporating the invention;

FIG. 2 is a schematic diagram illustrating the frame deletion process;and

FIG. 3 is a schematic diagram illustrating the frame insertion process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to the drawings, FIG. 1 is a block diagram of a video andaudio processing system incorporating the invention. As seen in thisfigure, the video and audio portions of standard program signals (e.g.NTSC, PAL, SECAM or the like) are initially separated into theindividual video and audio components using conventional circuitry (notshown). The video portion is applied to the input of a first signalprocessor unit 12 incorporating an analog to digital converter 14, adigital video memory 15, and a digital to analog converter 16. The videois first converted from analog to digital form in analog to digitalconverter 14 and stored in digital video memory 15. Digital video outputfrom digital video memory 15 is converted back to analog form in digitalto analog converter 16 and supplied to a first output terminal 17 astime changed video.

Similarly, the audio portion of the programming material is supplied toan audio signal processing unit generally designated with referencenumeral 22 and including an analog to digital converter 24, a digitalaudio memory 25, and a digital to analog converter 26. The audio portionof the programming material is thus converted from analog to digitalform in analog to digital converter 24, stored in digital form indigital audio memory 25, and converted from digital to analog form indigital to analog converter 26. The analog output from digital to analogconverter 26 is supplied to a second output terminal 27 as time chargedaudio. Analog to digital converters 14, 24 and digital to analogconverter 16, 26 are conventional units having an appropriate bit size(e.g. 8 bits per sample) and a clocking speed compatible with thefrequency content of their respective input signals. For example, theclock rate for analog to digital converter 14 used in the preferredembodiment is 13.5 MHz, although other clock frequencies may be employedso long as they comply with the known requirements of sampling theory.The bit size used in the preferred embodiment for analog to digitalconverter 24 is 16 bits per sample, and the clock rate employed is 48KHz. Similar considerations apply to digital to analog converters 16 and26.

Digital video memory 15 is a conventional digital storage unit having acapacity at least equal to the maximum accumulation time expected to beafforded by the system. For example, for a system designed to accumulate30 seconds worth of frame time over a one-hour total interval, digitalvideo memory 15 would have a capacity to store at least 900 frames ofNTSC video. Similar considerations apply to digital audio memory 25:however, the total storage capacity of digital audio memory 25 may besubstantially less than that of digital memory 15 due to the lowerfrequencies at which audio is conveyed. In the preferred embodiment,digital audio memory 25 has a storage capacity of 30 seconds (i.e., thesame time storage capacity of digital video memory 15).

Video processing unit 15 incorporates circuitry termed a Δ segmentcircuit 18 which may be manually overridden by a manual video control19. The purpose of the Δ segment circuitry 18 is to either delete orinsert frames of video from the sequence of frames stored in digitalvideo memory 15 on a programmed basis. Frame deletion is done by simplyskipping over a frame in the normal sequence of frames and is describedbelow with reference to FIG. 2. Frame insertion is accomplished bysimply repeating a given frame in the frame sequence and is describedbelow with reference to FIG. 3. In the periodic mode of operation, theframe deletion or insertion rate is set by the manual control 19, whichthe operator uses to dial in the total number of frames or amount oftime to be deleted or added to the original program content during theinitial stage of the signal processing. Thus, for example, if theoperator wishes to delete ten seconds of time over a one-hour period,that number is entered by means of manual control 19 into the Δ segmentcircuit 18, and the circuitry periodically deletes every ith frame untila total of 10 seconds worth of frame time has been deleted or saved.

During the periodic frame deletion or insertion processing, a ΔV circuit20 keeps track of the total time value of the deleted or insertedframes. ΔV circuit 20 essentially comprises a counter which receivesframe deletion or insertion signals from the segment circuit 18 andeither increments or decrements in response to each deleted or insertedframe.

Audio processing circuit 22 is provided with similar Δ segment circuitry28 and Δ audio circuitry 30 for the similar purpose of deleting oradding audio segments and keeping track of the total time value of thesegments deleted or inserted. Δ segment circuit 28 is controlled bymanual control unit 19 in tandem with Δ segment circuit 18. However, theactual audio portions which are deleted or repeated need not correspondexactly to the same frames which are deleted or repeated by videoprocessing unit 12: in fact, the audio portions which are deleted orinserted may be segments of audio signals from different frames. It issufficient that any time delay between the video and the audio signalportions subjected to the time variation processing and presented tooutput terminals 17, 27 not exceed ±3 video frames, with a maximumdifference of ±1 frame being preferred. By observing these constraints,no lip sync error is introduced to the original programming material inan observable fashion.

As indicated by the legends GL and External Sync Gen, the videoprocessing unit 12 may be coupled to and driven by an external syncgenerator, such as a studio sync generator, so that the video processingcan be done in synchronous fashion with other video broadcasting orreproduction equipment.

FIG. 2 is a schematic diagram illustrating the frame deletion process ineither the periodic or manual mode. As schematically represented in thisfigure, the leftmost column represents the sequence of video framesincoming on input terminal 10 into the video processing unit 12. Themiddle column labeled video out represents the sequence of outgoingframes after processing is done. The rightmost column indicates thetotal number of frames deleted. The process begins by specifying withmanual control unit 19 the number of frames to be deleted or the timevalue of these frames to the Δ segment unit 18. Thereafter, the firstfour frames (F1-F4) are simply passed through the processing unit 12essentially unaffected. Frame 5 (F5), however, is deleted and replacedwith frame 6 (F6), and frames 7-9 (F7-F9) are output in sequence afterframe 6. Similarly, frame 10 (F10) is deleted, and frame 11 (F11) isoutput after frame 9 (F9). After five frame times, one frame is deleted;after ten frame times, two frames are deleted, etc. up until the desiredtotal number of frames n (or the time corresponding thereto).Thereafter, the frames are simply passed through the digital videomemory 15 essentially unaffected (since the total desired amount of timehas already been accumulated).

During the frame deletion process, corresponding segments of audio aresimilarly deleted. However, the audio segments need not correspondexactly to the frames deleted. Stated differently, portions of audiofrom one frame may be deleted along with portions of audio from apreceding or succeeding frame; or all of the audio of a given frame maybe deleted, as desired. The manner in which the audio segments areactually chosen for deletion will depend upon the frequencycharacteristics of the audio encountered, and are chosen in order tominimize the introduction of any audible noise signals into the finaloutput signals.

FIG. 3 is a schematic diagram illustrating the frame insertion processin order to expand the total run time of the program material. Thisprocess is essentially the reverse of the frame deletion process andproceeds by specifying the total number of frames or the time equivalentto be inserted into the length of the program material using manualcontrol unit 19, followed by processing of the successive frames ofvideo (and corresponding audio) to repeat every ith frame until thetotal number of frames (i.e., the desired time) have been accumulated.

Appendix A to this application contains a discussion of the timeequations which apply to proper operation of the invention.

As noted above, Δ segment circuits 18, 28 can be manually overridden bymanual control unit 19 to provide operator controlled frame insertion orframe deletion. In the preferred embodiment, manual control unit 19includes a rotatable knob with a detent feel. Rotation of the knob inthe clockwise direction provides one inserted frame per detent; whilerotation of the knob in the counter-clockwise direction results in oneframe deletion. Not illustrated in the figure is a display unit, whichmay be any one of a number of conventional display devices (e.g. an LCDdisplay) which indicates the total number of frames or total time valueselected by the manual control unit 19 and, if desired, the runningtotal of ΔV and ΔA.

Returning to FIG. 1, a third mode of operation—termed auto mode—is alsoprovided according to the invention. In this mode of operation, thetotal number of frames or total amount of time to be deleted or insertedis again specified by manual control unit 19: however, the actual choiceof which particular frames are to be deleted or inserted and whichparticular audio segments are to be deleted or inserted, isautomatically controlled by a pair of detector circuits. Control of thevideo frame deletion/insertion is done by a motion detector circuit 40which incorporates any one of a number of known algorithms fordetermining the amount of motion change between adjacent frames, andpermits deletion/insertion of a given frame whenever the change inmotion between the frames does not exceed a selected threshold value.Such circuits are well known and have been used in video compression andcoding systems. However, motion detect circuit 40 is constrained toeither delete or insert a specified total number of frames over a fixedperiod of time in accordance with the parameters specified by manualcontrol unit 19. Consequently, motion detect circuit 40 is provided withthe accumulated total count from circuit 20, and an internal timing unit(not illustrated) in order to measure the progress of the frame deletionor insertion processing. If the total number of deleted or accumulatedframes runs behind the elapsed real time (due to program content withrelatively large amounts of motion over a large sequence of frames), themotion detect threshold is automatically raised by motion detect circuit40 in order to permit a relatively larger number of frames to be deletedor inserted so that the system will succeed in deleting or inserting thedesired amount of time over the prescribed total program real timeperiod.

Similarly, a pitch and level detect circuit 50 selects which audioportions contain the most effective frequencies and amplitudes capableof being deleted with minimal impairment to the audio (e.g. by notintroducing “pops” or “clicks” into the audio). Pitch and level detectcircuit 50 is similarly supplied with the running total from the ΔAcircuit 30, and is provided with a threshold adjusting circuit to enablethe threshold to be raised if the audio deletion processing is runningbehind the total elapsed time of the real time program.

The sensitivity threshold of circuits 40 and 50 may also be functionallycoupled to the amount of time change desired, as suggested by thediagonal arrows overlying elements 12, 22, 40 and 50. Thus, for amaximum amount of time change, the sensitivity thresholds are raised,while for a minimum amount of time change, the sensitivity thresholdsare lowered.

Both motion detect circuit 40 and pitch and level detect circuit 50 areprovided with control output lines 42, 52 which are used to control theΔ segment circuits 18, 28 on an on-the-fly basis. Thus, for example,motion detect circuit 40 may determine that three successive frames areto be deleted from the frame sequence: in such a case, a control signalis issued on control line 42 to the Δ segment circuit 18 to delete thethree identified successive frames. Similarly, pitch and level detectcircuit 50 will determine those audio segments which are to be deletedfrom frame portions, and issues control signals on control line 52 tothe Δ segment circuit 28.

In order to ensure that the total time delay between the time changedoutput video on terminal 17 and the time changed output audio onterminal 27 does not exceed the preselected maximum frame difference(i.e., ±1 frame time in the preferred embodiment), the accumulated videotime and accumulated audio time are coupled from the a ΔV circuit 20 andΔA circuit 30, respectively, via motion detect circuit 40 and pitch andlevel detect circuit 50 to an A/V phase difference comparator 60. In theevent that the video portions and the audio portions on the outputterminals 17, 27 are close to the maximum separation difference, thecomparator 60 issues control signals on control lines 61, 62 to themotion detect circuit 40 and pitch and level detect circuit 50. Thesecontrol signals are then used by circuits 40. 50 to select video framesand audio segments for deletion or insertion which steer the A/Vdifference in the proper direction.

Some program materials may include segments which should not be subjectto frame deletion or insertion due to the nature of the subject matter.For example, some commercial providers may require that the commercialprogramming information not be altered in any way. In such cases, it isuseful to provide a pause function which terminates frame deletion andframe insertion until the sensitive programming material has been passedthrough the signal processing units 12, 22. This function is provided bydisabling operation of the Δ segment circuits 18, 28, as well asoperation of the manual control 19. The pause function may beimplemented in the form of a manually operable switch—e.g. a push buttonswitch—and an indicator specifying the state of the pause functioncircuit; or may be automatically implemented using appropriate circuitryfor detecting predetermined codes or other markers in predeterminedportions of the video frames. For example, a special character may beinserted in the vertical blanking interval specifying the first frame ina sequence of frames for which the pause function is required; and anend of sequence special character may be inserted in the last frame.Such a character may be conveniently inserted during non-viewableportions of a frame, such as in the vertical blanking interval. Otherspecific implementations of the pause function will occur to thoseskilled in the art.

As will now be apparent, the invention is capable of increasing anddecreasing passages of time in programming material by significantamounts, without impairing the subjective quality of the programmingmaterials as viewed. For example, for NTSC video, by deleting one out ofevery twelve frames, a total of five minutes per hour can be accumulatedor “saved” for other purposes. Similarly, by adding an additional frameevery six frames in NTSC video ten minutes per hour can be added to thetotal running time of programming material. In addition, it should benoted that the removal of audit segments at different points in timefrom the video frames optimizes the quality of the final video/audiooutput from the system, since it enables separate alteration of thevideo and audio portions based on the information content and usingtechniques which are optimal to video signals and audio signalsseparately. This ensures that the quality of the finally producedprogramming material is nearly as high as the original material.

While the above provides a full and complete description of thepreferred embodiments of the invention, various modifications, alternateconstructions and equivalents may be employed, as desired. For example,while the invention has been described with reference to deletion andinsertion of frames of video, these principles apply to deletion andinsertion of individual fields of information. Therefore, the abovedescription and illustrations should not be construed as limiting thescope of the invention, which is defined by the appended claims.

APPENDIX A

For this machine the following time equations must hold true:

ΔT _(V)=Σ_(o) ^(n) Δtv

and

T _(A)=Σ_(o) ^(an) Δt _(A)

Where:

ΔT_(V)=Total accumulated Video delay (+/−) time

ΔT_(A)=Total accumulated Audio delay (+/−) time

Δt_(V)=Time duration of each Video packet (usually one frame)

Δt_(A)=Time duration of each Audio packet (about 5 mil. sec. for thisexample)

n=Number of Video packets needed to achieve total time change desired

a=ratio between the time duration of the video and audio packets.

For the machine to work:

ΔT _(V) =ΔT _(A)  1)

or

ΔT _(A) =ΔT _(V) ±Δt _(V)  2)

These statements must hold to accomplish the desired time change (+/−)while maintaining lip-sync. Equation 1) holds for exact lip-sync whileEquation 2) holds for minimum picture and sound anomalies.

“Time Machine” run modes:

Manual—where a knob can be turned clock wise or counter clock wise toincrease or decrease time in frame increments.

Auto—where a preset amount of time change (+/−) will automaticallyaccrue where the audio and video can be locked together (ΔT_(V)=ΔT_(A))or run independently (ΔT_(A)=ΔT_(V)±Δt_(V))

“Time Machine” features:

Time change accrual can be stopped and restarted to coincide with suchsacred timed segments as commercials.

Motion, pitch and level change sensitivity can be adjusted to speed upor slow down the rate of time change accrual.

Maximum number of packet chances per second can be set to minimizeexcessive changes in time in the Auto mode.

What is claimed is:
 1. An apparatus for altering the total running timeof an original program signal in real time to generate a time-alteredprogram signal, the original program signal including an original videoprogram signal that includes a plurality of video signal elements insequence, each video signal element having a predefined length of videotime associated therewith, the original program signal also including anoriginal audio program signal, the original audio program signalincluding a plurality of audio signal segments in sequence, each audiosignal segment having the predefined length of audio time associatedtherewith, each video signal element having one or more correspondingaudio signal segments associated therewith, the apparatus comprising:(a) a video analog-to-digital converter (ADC) that receives the originalvideo program signal and converts each video signal element of theoriginal video program signal to corresponding digital video data; (b) avideo data processor that compares digital video data received from thevideo ADC and corresponding to adjacent video signal elements in saidsequence of video signal elements, determines an amount of motiondifference between said adjacent video signal elements, and deletesdigital video data corresponding to a video signal element if the motiondifference between said adjacent video signal elements is less than orequal to a predefined motion difference threshold value to provide atime-shortened sequence of digital video data; (c) a digital videomemory buffer that stores digital video data received by the digitalvideo memory buffer from the video data processor; (d) an audioanalog-to-digital converter (ADC) that receives the original audioprogram signal and converts each audio signal segment of the originalaudio program signal to corresponding digital audio data; (e) an audiodata processor that compares digital audio data received from the audioADC and corresponding to adjacent audio signal segments in said sequenceof audio signal segments, determines an amount of audio signaldifference between said adjacent audio signal segments, and, for eachvideo signal element deleted from the original video program signal,deletes digital audio data corresponding to one or more audio signalsegments, such that the amount of deleted audio time substantiallycorresponds to the predefined length of time associated with the deletedvideo signal element, based upon the amount of audio signal differencebetween adjacent audio signal segments to provide a time-shortenedsequence of digital audio data; (f) a digital audio memory buffer thatstores digital audio data received by the digital audio memory bufferfrom the audio data processor; (g) a video digital-to-analog converter(DAC) that converts a sequence of digital video data output by thedigital video memory buffer to a corresponding time-shortened analogvideo program signal; (h) an audio digital-to-analog converter (DAC)that converts a sequence of digital audio data output by the digitalaudio memory buffer to a corresponding time-shortened analog audioprogram signal; (i) circuitry that provides the time-shortened analogvideo program signal and the time-shortened analog audio program signalas a time-shortened broadcast program signal; and (j) a thresholdadjustment element for raising the motion difference threshold valueon-the-fly such that, if the total number of deleted video signalelements runs behind a programmed elapsed time, whereby the motiondifference threshold value is automatically raised to permit a largernumber of video signal elements to be deleted.
 2. An apparatus thatautomatically alters the total running time of an original programsignal in real time to generate a time-shortened program signal, theoriginal program signal including an original video program signal thatincludes a plurality of video frame signals in sequence, each videoframe signal having a predefined frame time associated therewith, theoriginal program signal also including an original audio program signal,the original audio program signal including a plurality of audio signalsegments, each audio signal segment having the predefined audio segmenttime associated therewith, each video frame signal having one or morecorresponding audio signal segments associated therewith, the apparatuscomprising: (a) a video analog-to-digital converter (ADC) that receivesthe original video program signal and converts each video frame signalelement of the original video program signal to corresponding digitalvideo data; (b) a video data processor that compares digital video datareceived from the video ADC and corresponding to adjacent video framesignal in said sequence of video frame signals, determines an amount ofmotion difference between said adjacent video frame signals,and:automatically deletes digital video data corresponding to a videoframe signal if the motion difference between said adjacent video framesignals is less than or equal to a predefined motion differencethreshold value to provide a time-shortened sequence of digital videodata; (c) a digital video memory buffer that stores digital video datareceived by the digital video memory buffer from the video dataprocessor; (d) an audio analog-to-digital converter (ADC) that receivesthe original audio program signal and converts each audio signal segmentof the original audio program signal to corresponding digital audiodata; (e) an audio data processor that compares digital audio datareceived from the audio ADC and corresponding to adjacent audio signalsegments in said sequence of audio signal segments, determines an amountof audio signal difference between said adjacent audio signal segments,and, for each video frame signal deleted from the original video programsignal, automatically deletes digital audio data corresponding to one ormore audio signal segments, such that the amount of deleted audio timesubstantially corresponds to the predefined length of time associatedwith the deleted video frame signal, based upon the amount of audiosignal difference between adjacent audio signal segments, to provide atime-shortened sequence of digital audio data; (f) a digital audiomemory buffer that stores digital audio data received by the digitalaudio memory buffer from the audio data processor; (g) a videodigital-to-analog converter (DAC) that converts a sequence of digitalvideo data output by the digital video memory buffer to a correspondingtime-shortened analog video program signal; (h) an audiodigital-to-analog converter (DAC) that converts a sequence of digitalaudio data output by the digital audio memory buffer to a correspondingtime-shortened analog audio program signal; and (i) circuitry thatprovides the time-shortened analog video program signal and thetime-shortened analog audio program signal as a time-shortened broadcastprogram signal.
 3. An apparatus as in claim 2, and further comprising abroadcast system that broadcasts the time-shortened broadcast programsignal substantially simultaneously with generation of thetime-shortened broadcast program signal.
 4. An apparatus as in claim 2,and further comprising means for combining an additional program signalwith the time-shortened broadcast program signal to generate a newprogram signal.
 5. An apparatus as in claim 4, and wherein theadditional program signal comprises a signal corresponding toadvertising information.
 6. An apparatus as in claim 2, and furthercomprising a counter that counts total cumulative time deleted from theoriginal video program signal.